According to the data on the official website, these are the supported operating systems where Primer Express can be installed on:
Compatible Operating Systems: Windows 7 32-bit (QuantStudio™ controlling or non-instrument controlling computers only) and Windows XP (StepOne®, StepOnePlus®, 7300, 7500, 7500 Fast, 7900HT, ViiA™ 7 instrument controlling and non-instrument controlling computers).
As you can see, there is no Mac OS availability, therefore installation on this operating system is currently not possible. But there are other options as well: install Windows through Bootcamp or Parallels Desktop.
